What Happens To a Query If It Times Out?

Question

Let\'s say I have a query that is sent to my SQL-Server database, it takes more than 30 seconds, and my program throws an SQL Query Timeout exception. Is the query still ch

Answer 1

Before executing a query, SQL Server estimates how much memory it needs to run and tries to reserve this amount of memory from the buffer pool. If the reservation succeeds the query is executed immediately. If there is not enough memory readily available from the buffer pool, then the query is put into a queue with a timeout value, where the timeout value is guided by the query cost. The basic rule is: higher the estimated cost is, larger the time out value is. When the waiting time of this query exceeds the timeout value, a time out error is thrown and the query is removed from the queue.

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